Assign xc7 prefix to prjxray tools to avoid conflicts

[acomodi]

All the tools in prjxray should have an xc7 prefix, so to make them unique.

E.g. bitread or bittool could enter in conflicts with other tools names.

[slayer321]

Hey, I new to open source and want to contribute ........ can you guide me how can I start with this issue?

[acomodi]

Hi @slayer321, basically the bitstream tools in here should have a common prefix, similarly to xc7frames2bit. I think this issue should only go as far as renaming the tools' names.

[slayer321]

ok........ so you mean all the tools in here name must prefix with xc7 that's what need to done? If that's the case then I can do it

[slayer321]

I have send a PR #1668 .. do check and let me know if everything is correct